They drink (stored) rain water and clad themselves with wool. They move about barefooted on clean ground and pass their time amdist bushes which is a danger-free retreat for them. Since they are oblivious of self, they are indifferent to anything untoward. They are definitely not disobedient (to the Divine Commandments). Please see that you do not harass those who already are alien to comforts.
Note: In this verse Shah has delineated the true momin as under:
1) That he is simple in his living,
2) That he is oblivious of ‘self’, i.e. he is self-abnegations.
3) That he is not influenced by any unusual happening; and
4) That he carries out all Divine Commandments.

Their feet on clean ground, rain water their drink,
wool their covering,
Their abode under cluster of trees has no threat essly they,
Live, forgetting self, They are not defiant, Umar! do not harm to them.

Rain water they drink, woolies they wear, bare foot they move about,
Cluster of trees is their meeting place where they relax without risk,
Unselfconscious of themselves they live free from fears,
Umer, they are not defiant, don't harm those miserable.